Nanode thermometer

11Feb12

I first heard about Nanode (a low cost board that brings together Arduino and ethernet) via Andy Piper, then a few days later I had the fortune of seeing its creator Ken Boak speak at London’s Open Source Hardware Users Group (OSHUG). The week afterwards Ken was at the excellent Monkigras event, and did a short talk about Nanode; best of all, he had some with him. I picked up a Nanode RF kit for £20 and put it together that evening.

Nanode RF - mine doesn't have the RFM12B transceiver fitted

All did not go exactly according to plan. At first the only instructions I could find were for the older Nanode 5. I got to the point where I had a running system, but programming wasn’t working. A bit more digging around turned up the correct Nanode RF build guide, and I realised that I’d missed out putting in a voltage jumper (step 25). I was then able to get some code onto my Nanode, though more by good luck than good planning – I was still unaware of the vital step of pressing the reset button when a sketch finishes building (but immediately before it starts downloading) – that took some trial and error to discover.

Once I had a working Nanode I could see it connecting to my home network, and then serving basic web pages. The time had come for a basic application. Since we were in a cold snap, and snow was forecast I though a temperature sensor would be fun. I found some code for a thermistor based project, and adapted it to the TMP36 temperature sensor that comes with the Oomlout ARDX kit. I then popped it out in the garage so I could measure the external temperature (but have a handy network connection).

It’s still really cold! Most of the week it’s been around -3C, but it obviously took a plunge last night. I’m now wishing I’d done something more sophisticated so I could log temp over time and draw charts. I feel some tinkering with MQTT coming on.